Minimally invasive surgical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. As a consequence, the average length of a hospital stay for standard surgery may be shortened significantly using minimally invasive surgical techniques. Also, patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally invasive surgery.
A common form of minimally invasive surgery is endoscopy, and a common form of endoscopy is laparoscopy, which is minimally invasive inspection and/or surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient's abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately one-half inch or less) incisions to provide entry ports for laparoscopic instruments.
Laparoscopic surgical instruments generally include an endoscope (e.g., laparoscope) for viewing the surgical field and tools for working at the surgical site. The working tools are typically similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube (also known as, e.g., an instrument shaft or a main shaft). The end effector can include, for example, a clamp, grasper, scissor, stapler, cautery tool, linear cutter, or needle holder.
To perform surgical procedures, the surgeon passes working tools through cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon views the procedure from a monitor that displays an image of the surgical site taken from the endoscope. Similar endoscopic techniques are employed in, for example, arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.
Minimally invasive telesurgical robotic systems are being developed to increase a surgeon's dexterity when working on an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location (outside the sterile field). In a telesurgery system, the surgeon is often provided with an image of the surgical site at a control console. While viewing a three dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the control console. Each of the master input devices controls the motion of a servo-mechanically actuated/articulated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools. Many of the telesurgical tools have jaws or other articulatable end effectors that perform various functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting tissue, or the like, in response to manipulation of the master input devices. Tools having distal wrist joints allow the surgeon to orient the tool within the internal surgical site, greatly enhancing the freedom with which the surgeon can interact with (and treat) the tissue in real time.
Telesurgical systems are finding increasing applications by surgeons for growing variety of therapies. New tools would help to continue this growth, and particularly tools such as staplers, linear cutters, and the like (which are capable of imposing significant clamping and other forces against the internal tissues). Unfortunately, it can be challenging to transmit the desired telesurgical end effector forces through known tool wrists, particularly while retaining the response time, precision, flexibility, and reliability in the tool that is desired for telesurgical tasks.
For example, non-robotic surgical tools comprising linear clamping, cutting, and stapling devices have been employed in many different surgical procedures. Such a tool can be used to resect a cancerous or anomalous tissue from a gastro-intestinal tract. Unfortunately, many known surgical tools, including known linear clamping, cutting, and stapling tools, lack the ability to transmit desired torques (e.g., tissue clamping torque) or forces (e.g., staple firing force) across a compact articulated wrist, which may reduce the effectiveness of the surgical tool. Alternative tools with a shaft driven clamping mechanism also fail to provide rotational movement of an end effector to mimic the natural action of a surgeon's wrist.
For the reasons given above, it is desirable to provide improved surgical and/or robotic wrist structures. It would also be desirable to provide improved minimally invasive surgical tools that include a wrist mechanism that mimics the natural action of a surgeon's wrist, while allowing enhanced end effector forces and a response time suitable for telesurgical control.